The Democratic Party of Japan is likely to become the most powerful party in the Tokyo Metropolitan Assembly in Sunday's election, overtaking the Liberal Democratic Party, a Kyodo News opinion poll indicated.

Of 1,037 randomly chosen voters in Tokyo polled over the weekend by phone, 30.3 percent said they will vote for candidates backed by the DPJ.

The figure was up 13.2 percentage points from a survey before the last Tokyo election in 2005 and far higher than the 18.2 percent who said they would vote for the LDP. The rate of respondents supporting LDP-backed candidates was down 8.5 points from 2005.